My favorite Vaping in public story was last year, I was at an event at Honda Center (a 18,000 seat arena in California)... out of courtesy i went outside to the smoking section to Vape...
It was raining lightly so i stood closer to the doors than where they allow smokers... a police officer saw me exhale and said, "you need to stand behind the planters if you're going to smoke".
I replied, "well, I'm not really smoking"
His response amazed me, "Oh it's electronic, sorry I just saw you exhale... why the hell are you out here in the rain... go back inside... you're not smoking"
I ended up staying outside for a bit talking with the 2 cops... who were very cool...
But I've never bothered to step outside to Vape at Honda Center again.